Rotary impact attachment



1959 E. .1. ONDECK 2,916,117

ROTARY IMPACT ATTACHMENT Filed June 9, 1955 4 Sheets-Sheet l INVENTOR.

Zj/mer I Dmi- 1 J. ONDECK 2,916,117

ROTARY IMPACT ATTACHMENT 4 Sheets-Sheet 2 Filed June 9, 1955 VENTO F 172261"! O JZQ e Dec. 8, 1959 E. J. ONDECK 2,916,117

ROTARY IMPACT ATTACHMENT Filed June 9, 1955 4 Sheets-Sheet 3 IN V EN TOR.

fig mar [Qndec Dec. 8, 1959 E. .1. ONDECK ROTARY IMPACT ATTACHMENT 4 Sheets-Sheet 4 Filed June 9. 1955 States Patent Cffice 2,915,117 Patented Dec. 8, 1959 ROTARY IMPACT ATTACHMENT Elmer J. Ondeck, Brookfield, 111., assignor, by mesne assignments, to Supreme Products Corporation, Chicago, 111., a corporation of Illinois Application June 9, 1955, Serial No. 514,354

Claims. (Cl. 1923.5)

This invention relates to rotary impact tools and more particularly to a screw driver or nut runner effecting impact engagement and positive disengagement of clutch impulse sharply delivered.

Consequently, it is one of the objects of the invention to provide an externally vibrationless impact clutch drive wherein impact striking power is stored in members that receive the power and deliver the power torquewise without cams and without frictional losses.

' A further object of the invention is to provide an improved impact clutch which is reversible in direction of rotation and all moving parts can be lubricated without loss of power.

It is also an objective of the present invention to provide a rotary impact tool which does not clear the engagement between one clutch member and another until a predetermined amount of torque is developed between them, so that successive impacts between the clutch elements are rapid and uniform hammer-type blows.

Another object is to provide a rotary impact tool having means for accumulating energy when the clutch members thereof are engaged and for driving one of the clutch members along a helical path with the energy thus accumulated when the clutch members are disengaged to "convert such energy into high impact torque.

Anotherobject is to provide a plurality of substantially sector-shaped teeth on the mating faces of each of the clutch members of the rotary impact tool of the invention, the radially aligned sides of the teeth being subthe clutch members engaged with increasing torque accumul'ating effect until a predetermined level of torque is 'achievedbefore each impact blow is delivered.

Another object of the invention is 'to provide a rotary impact tool of the type indicated which may be driven in eit her direction of rotation, and with a reversible gear system adapted to effect selective reversal of the screw driver or nut runner'if the source of power is not readily reversible.

"Other objects and advantages of the invention will become evident as the description proceeds in accordance with the drawings, in which:

Fig. 1 is a vertical sectional vi ew of a rotary impact tool and clutch elements therefor taken alongline 1- 1 bf Fig. 2;

Fig. 2 is a horizontal sectional view of the impact tool of the invention taken along the line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectional view of the tool of the invention taken along the lines 3-3 of Fig. 1;

Fig. 4 is an exploded perspective view of the clutch elements of the invention in a particular embodiment thereof;

Fig. 5 is a fragmentary side elevational View of the embodiment of Fig. 4 showing the clutch elements in driving engagement;

Fig. 6 is a similar view to that seen in Fig. 5 showing the clutch elements in disengaged relation;

Fig. 7 is a vertical sectional view of another embodiment of the invention disclosing also a bevel gear system adapted to effect selective reversal of the direction of angular rotation of the tool;

Fig. 8 is a fragmentary side elevational view of the impact elements of the invention in disconnected relationship and as taken through the line 8-8 of Fig. 7;

Fig. 9 is a horizontal sectional View of the embodiment of the invention of Fig. 7 taken through the line 99 of Fig. 7; and

Fig. 10 is a horizontal sectional view taken through the line Iii-10 of Fig. 7.

Referring now to Fig. l, a particular embodiment of the rotary impact tool 19 of the invention is disclosed wherein a casing 12 having a cap 14 secured to a cylindrical body portion 16 is adapted to have journalled therethrough the spindle 18. The spindle 18 has an upper portion 19 of reduced diameter adapted to be keyed to a prime mover (not shown) conventionally used to power a screw driver or nut runner of conventional form, and a lower portion 21 of reduced diameter journalled within the clutch member 20. The clutch member 20 is journalled at the same level in the casing 16 to maintain alignment of parts and their relative working positions.

A complementary clutch member 22 is provided which is adapted to engage in rotary drive relationship with the clutch member 20 by means of complementary teeth 24 and 26 on the clutch elements 22 and 26 respectively, as seen in Fig. 3. The teeth 24 and 26 are preferably given a sector-shaped configuration and their radial sides 27 are preferably substantially vertical as shown in Figs. 3, 4 and 5 so that the driving engagement either by rotary pressure or impact blow is transmitted from the clutch member 22 to member 23 solely as torque, as will be ly and torsionally flexing spring elements 28 are secured in radial slots 32 and 34 of bracket 3%} and clutch member 22 respectively with the planes thereof in resting position disposed radially of the spindle 13. The spring connection members 28 are normally disposed in vertical axial alignment with the spindle 18 to exert a downward and forward force adapted when flexed to drive and hold the respective clutch members 20 and 22 in mating engagement with each other. Accordingly, when torque is applied to the spindle, the teeth 24 on the upper clutch member 22 engage the teeth 26 on the lower clutch member 20 until the torque increases to a predetermined threshold level. During this transmission of torque, the spring elements. 28 will be given a partial twist and lateral flexing, as seen in Fig. 6, to store power. When the torque exceeds the predetermined level, the amount "of twist and flexing in the elements 28 will foreshorten 3 them along the vertical axis sufficiently to lift the upper clutch member 22 and the teeth 24 thereof above the clutch member 2i) and out of engagement with the teeth 26 thereon.

The springs thus serve not only as accumulators of a collective power, but will lift the teeth 24 over the surface of the teeth 26. Then When the teeth are released from engagement the members 28 under their stored power exert counter-axial and counter-torque forces in their effort to recover their resting position. Each tooth on the member 22 will follow an inclined defining a portion of a curve which ends substantially normal to the vertical face of a tooth upon the member 2% after the teeth 24 become disengaged with the teeth 26. The resultant horizontal component of the vector will, from accelerated momentum of member 2%, be several times the torque applied to the spindle 13, so that the member 22 will impart a heavy impact torque to member 2% when teeth 24 strike the teeth 26 along their vertical interfaces.

It Will be appreciated that each time the aforementioned predetermined amount of torque for spindle 18 has been reached, the action described will follow and be uniform throughout a rapid succession of impacts to turn the nut or screw. Moreover, the storage and expenditure of energy will be unusually efiicient in the operation of the tool because frictional losses are eliminated. In fact, lubrication of the teeth will not reduce the striking power.

As seen in Fig. 4, it is preferred to use a pair of oppositely-aligned teeth on each clutch member for rotation in either direction, but this feature of the invention may be varied without altering the essential conception thereof.

Referring now to Fig. 7, a second embodiment of the invention is disclosed wherein a plurality of elongated U-shaped hinge or swing links 35 are loosely pivoted at opposite ends in bracket member 3b and the clutch memher 2 3, respectively, in supporting relation thereto. For this purpose, the bracket member 38' is provided with spaced radially extending apertures 38 to receive the upper ends it of the J-shaped hinge members 36 and a plurality of corresponding bores 42 are formed in the clutch member 22 to receive the lower ends 49 of the hinges. Annular rings 4?: and 58 are seated on the flange elements 52 and 54 of the bracket 3t? and clutch 22, respectively, and are adapted to retain the hinge elements in axial alignment with the spindle 18.

A torsion spring 56 is secured to the annular boss 58 of the bracket member 36 at its upper end and to the boss 60 of relatively reduced diameter on the clutch member 22 at its lower end. The torsion spring 56 is preferably formed of fiat spring steel having an axial dimension substantially greater than its dimension in the assembled clutch so that the member 56 exerts a heavy sustained downward force upon the clutch member 22 which serves to bias the clutch members Zil and 22 into mating engagement. When the torque developed reaches a predeterined level, the swinging effect of the links 36 will exert a compression effect on the torsion spring 56 and lift the clutch member 22 upwardly with a positive action to cause the teeth to disengage, whereupon the teeth 24 pass over the teeth 26 as seen in Fig. 8.

In doing this, the swing elements 36 follow an arcuate path during elevation of the clutch 22 out of engagement with the clutch 2d, and when the teeth 24 have moved across the teeth 26, these swings afford a pendulation for the clutch 22 downwardly along a circular path until the clutch member 22 drives against the clutch 20 for impact engagement between the respective teeth along an axis normal to the interfaces, to produce the efficient conversion of accumulated energy into torque referred to.

The tendency of the torsion spring 56 to expand downwardly will impart an accelerated momentum to the clutch 22 along its path of movement into the impact engagement with clutch 20. A coil spring 64 may also be provided between the annular bearing plate 66 secured axially to the spindle. 18 and the annular boss or flange 68 on the clutch 22 to bias the clutch 22 away from the annular bracket 30 so that additional accelerated force is imparted to the clutch 22.

The torsion spring 56 and helical spring 64 will provide rapid and powerful impact action between the clutch members 20 and 22 regardless of the direction of rotation of the spindle 18, as will the springs 28 in the embodiments of Fig. 1. However, in order to provide for selective reversal of the direction of rotation of the tool, e.g., in tightening or loosening a nut, as desired, if the prime mover is not readily reversible, a reversing gear system 7i) is provided which may be fixedly secured to the spindle 18 above the bracket 30, by suitable means, such as by a radial screw '73 interlocking the overlap between a socket '74 and projection '76.

The gear system 7E; includes a housing 78, a first gear d9 aligned axially with spindle 18 and secured thereto as just described, and a second gear 82 spaced axially above gear and also journalled in the housing 78. A pair of bevelled pinions 84 and 85 are slidably mounted on an axle 86 for meshing engagement peripherally with the gears 89 and 82, the pinion 84 being secured against relative rotation with respect to the axle by means of spline construction 88 and the pinion 85 being rotatable on the said axle. The axle 86 is slidably journalled in an annular bearing 99 adapted to rotate axially in the housing 78 on suitable bearing shoulders Q2 and 94- formed therein, the housing being provided with an annular recess 96 adapted to permit the aforementioned axial movement of the shaft 86. A serrated clutch sleeve 23 is secured by suitable means such as the pin ltlt) to the shaft 86 and a complementary clutch member 162 is formed integrally with the pinion 85, the clutch member 98 being biased into mating engagement with the clutch member 162 by means of a suitable helical spring 106 seating against the inner face of the pinion 34 and against the shoulder 1% on the clutch 98. At the same time, a stud 111 having a head 112 is slidably mounted in the radial aperture 114 of the housing and is provided with an axial groove 116 adapted to receive a key member or projection 117 therein whereby the axial movement of the stud may be guided and limited. Preferably the aperture 116 is formed by means of a boss 118 formed integrally with the housing, and a helical spring 12%) is disposed axially on the boss in abutting relation with the head of the stud whereby to bias the stud radially outwardly of the housing. The stud 1 10 is provided with an extension 122 having a complementary configuration relative to the axle 86 as shown on Fig. 10.

When power is applied to rotate the gear 82, the pinions 84 and 85 which are, as stated, normally locked against relative rotation, will hold the gear 84 in fixed position relative to the gear 85 so that the gears 80 and 82 will rotate in the same direction and at the same speed thereby at the same time rotating the spindle 86 axially of the housing. However, when stud is pressed inwardly so that the head 112 abuts the boss 118, the camming surface 124 on the stud will be contacted with impact force by the bevelled edge portion 126 of the axle 86 as the axle is rotated clockwise, as shown in the embodiment of Figs. 7 and 10. Thus the axle will be cammed axially away from the stud 110 sufficiently to completely disengage the clutch members 98 and 1tl2. Thereupon, both pinions 84 and 35 will be free to rotate in opposite directions and with the axle held against further rotation by the said extension 122, the gear 80 will be caused to rotate in a direction opposite to that of gear 82. Since the pinions 84 and 85 are freed from mutually locked rotation by the camming action referred to before the shaft is brought to a standstill, there will be no stripping of gears such as might occur if the pinions 84 and 85 were suddenly forced to overcome the momentum of gear 80 and to turn it in an opposite direction of angular rotation before being cammed free from their mutually imum of torque is possible.

. locked relationship. If desired, suitable means for holding the stud in the depressed condition may be provided as, for example, a bayonet slot and slide key (notshown). It is, therefore, possible to use the tool for either inserting or extracting a screw'or tightening or loosening a bolt or nut by the simple expedient of pressing upon the stud member. Moreover, gear system '70 maybe used with the embodiment of Fig. 7 or Fig. 1 without departing from the concept of the invention.

An impact tool of unusual versatility and effectiveness has thus been provided, having means for positively effecting disengagement of the clutch members without friction so that greater uniformity of action with a max- Correspondingly, a positive driving accelerated momentum action for a golf-club-like whip engagement of the clutch members is achieved which transmits all of the energy accumulated during engagement of the clutch members directly into torque force for the nut runner or screw driver. Thus the ratio of the effective power of the tool to the power of the prime mover is greater than conventionally experienced during substantially the entire operation of tightening or loosening a bolt or inserting or removing a screw.

While I have herein set forth a particular embodiment of the invention in considerable detail, it will be readily apparent that considerable change in these details may be made without departing from the spirit and principles of the invention, as set forth in the following claims.

I claim: v

1. In a rotary impact tool, a cylindrical casing, a spindle journalled axially in one end of said casing, a

clutch member journalled to said spindle and journalled in the other end of said casing, a second clutch member slidably journalled on said spindle, said first and second clutch members having complementary sector-shaped teeth formed in predetermined spaced-apart relation on each of the mating faces of said clutch members, a bracket member secured axially on said spindle, a torsion spring extending axially along said spindle and having one end secured to said bracket and the other end secured to said second-named clutch and a plurality of links each having one end pivotally secured in said bracket member and the, other end pivotally secured in said second-named clutch member for pivotal movement about an axis radial to said spindle, said torsion spring and links cooperating to lift said second-named clutch member when predetermined torque is applied between said first and second-named clutch members and to direct said secondnamed clutch member down a helical path into impact engagement with said first-named clutch member when said teeth on said first and second-named clutch members respectively are moved out of engagement by said torsion spring.

2. The construction according to claim 1 wherein said second-named clutch member and said bracket are provided with annular bearing surfaces, and a helical spring is secured axially of said spindle against said bearing surfaces whereby to bias said second-named clutch member into engagement with said first-named clutch member :in cooperation with said torsion spring.

3. The construction according to claim 2 wherein a pair of axially aligned bearing rings are secured to said bracket member and said second-named clutch respectively adapted to retain said links in the said pivotal engagement with said bracket and clutch respectively and to provide said axial bearing surfaces for said helical spring.

4. In the construction according to claim 2, means for selective reversal of the direction of angular rotation of said tool comprising a housing member, a first gear journalled in said housing member and secured to said spindle axially above said bracket, a second gear journalled in said housing member in spaced relation above said first gear, a pair of pinions adapted to engage said first and second gears in meshing relationship periph- 6 erally thereof, an axle member having said pinions slidably mounted thereon, one of said pinions being fixed against relative angular rotation with respect to said axle and the other of said pinions being rotatable thereupon, means for slidably supporting said axle in said housing member for selective rotation axially of said housing member and of said axle and a clutch member fixedly secured to said axle and said other of said pinions respectively, means for urging said clutch members into mating engagement whereby to lock said pinions and said axle against relative rotation and to effect rotation of said first and second gears in the same direction and manually operable means adapted to disengage said clutch members whereby to cause said first and second gears to rotate in opposite directions.

5. In a rotary impact tool, a cylindrical casing, a spindle journalled axially in one end of said casing, a clutch member journalled on said spindle and in the other end of said casing, a second clutch member slidably journalled on said spindle, said first and second clutch members having sector shaped teeth formed in predetermined spaced-apart relation on each of the mating faces of said clutch members, a bracket member secured axially on said spindle, and a plurality of elongated flat springs securing said second-named clutch to said bracket and having the longitudinal axis thereof normally disposed in axial alignment with said spindle and the transverse axis thereof normally disposed in radial alignment with said spindle, said springs being adapted to twist and shorten axially when torque is applied between said clutch members and to lift the teeth of said secondnamed clutch member out of locking engagement with the teeth of said first-named clutch member upon appli cation of a predetermined amount of torque between said clutch members, said springs being adapted to accumulate torque energy imparted thereto during engagement of said teeth and to drive said second-named clutch memher along a helical path into impact engagement with said first-named clutch, said impacts being successive during application of said predetermined torque to impart successive torques to said first-named clutch substantially greater than the torque imparted to said spindle, means for selective reversal of the direction of angular rotation of said tool comprising a housing member, a first gear journalled insaid housing member and secured to said spindle axially above said bracket, a second gear journalled in said housing member in spaced relation above said first gear, a pair of pinions adapted to engage said first and second gears in meshing relationship peripherally thereof, an axle member having said pinions slidably mounted thereon, one of said pinions being fixed against relative angular rotation with respect to said axle and the other of said pinions being rotatable thereupon, an annular bearing adapted for axial rotation in said housing member, said axle being slidably mounted in said bearing in journalled relation thereto and a clutch member fixedly secured to said axle and said other of said pinions respectively, means for urging said clutch members into mating engagement whereby to lock said pinions and said axle against relative rotation and to effect rotation of said first and second gears in the same direction and manually operable means adapted to disengage said clutch members whereby to cause said first and second gears to rotate in opposite directions, said manually operable means including a cam element adapted to engage a complementary end portion of said spindle.

6. In a rotary impact tool, a cylindrical casing, a spindle journalled axially in one end of said casing, a clutch member journalled to said spindle and journalled in the other end of said casing, 21 second clutch member slidably journalled on said spindle, said first and second clutch members having complementary sector-shaped teeth formed in predetermined spaced-apart relation on each of the mating faces of said clutch members, a

bracket member secured axially on said spindle, a torsion spring extending axially along said spindle and havlng one end secured to said bracket and the other end secured to said second-named clutch and a plurality of hinge bars each having one end pivotally secured in said bracket member and the other end pivotally secured in said second-named clutch member for pivotal movement about an axis radial to said spindle, said torsion spring being adapted to be twisted as said second-named clutch member is disengaged from said first-named clutch member when predetermined torque is applied to said first clutch member by said second clutch member, said hinge bars being displaced angularly with respect to the axis of said spindle whereby said second clutch member is rotated by said torsion spring and said hinge bars so that upon reengagement with said first clutch member relatively great impact is afiorded.

7. In a rotary impact tool, a power spindle, a bracket member secured axially to said spindle, a plurality of connection means including a torsion element secured to said bracket, a clutch member secured to said bracket by said connection means in spaced relation thereto and journalled slidably on said spindle, a second clutch member journalled on said spindle, and a plurality of teeth on each of said clutch members adapted to engage with the teeth on the other of said clutch members, said connection means being adapted to locate said clutch members in normally engaged relation and to lift said first-named clutch member out of engagement with said secondnamed clutch member upon application of a predetermined amount of relative rotation therebetween and to direct said first-named clutch member along a downwardly helical path upon disengagement of said clutch member to impart impact torque to said second clutch member, said connection means comprising a resilient torsion element being secured at opposite ends to said bracket and first named clutch member in torque transmitting relationship, and a plurality of links having either extremity thereof journalled in said bracket and first-named clutch member respectively, said torsion element biasing said first-named clutch member into drive engagement with said second-named clutch member.

8. The combination called for in claim 7 including a compression spring interengaging said bracket and firstnamed clutch member to urge them axially away from each other a distance limited by said links.

9. The combination called for in claim 7 in which said bracket and first named clutch member have radially directed apertures therein and said links having their extremities engaging in said apertures to provide said journalled relationship.

10. In a rotary impact tool, a power spindle, a bracket member secured axially to said spindle, a plurality of connection means including a torsion element secured to said bracket, a clutch member secured to said bracket by said connection means in spaced relation thereto and journalled slidably on said spindle, a second clutch member journalled on said spindle, and a plurality of teeth on each of said clutch members adapted to engage with the teeth on the other of said clutch members, said connection means being adapted to locate said clutch members in normally engaged relation and to lift said firstnamed clutch member out of engagement with said second-named clutch member upon application of a predetermined amount of relative rotation therebetween and to direct said first named clutch member along a downwardly helical path upon disengagement of said clutch member to impart impact torque to said second clutch member, means for selective reversal of the direction of angular rotation of said tool comprising a housing member, a first gear journalled in said housing member and secured to said spindle axially above said bracket, a second gear journalled in said housing member in spaced relation above said first gear, a pair of pinions adapted to engage said first and second gears in meshing relationship peripherally thereof, an axle member having said pinions slidably mounted thereon, one of said pinions being fixed against relative angular rotation with respect to said axle and the other of said pinions being rotatable thereupon, means for slidably supporting said axle in said housing member for selective rotation axially of said housing member and of said axle and said other of said pinions respectively, means for urging said clutch members into mating engagement whereby to lock said pinions and said axle against relative rotation and to effect rotation of said first and second gears in the same direction and manually operable means adapted to disengage said clutch members whereby to cause said first and second gears to rotate in opposite directions.

References Cited in the file of this patent UNITED STATES PATENTS l ,45 0,5 3 6 

